Gas heater



Oct. 27, 1953 w, MORAN 2,656,833

GAS HEATER Filed Oct. 14, 1948 W 5 Sheets-Sheet l WILL/AM O. MOEAN INVENTOR.

ATTORNE Y5 Oct. 27, 1953 w. o. MORAN 2,656,833

GAS HEATER Filed Oct. 14, 1948 5 Sheets-Sheet 2 W/LL/AM OMO/EAN INVENTOR.

ATTORNEYS W. O. MORAN Oct. 27, 1953 GAS HEATER 5 Sheets-$heet 3 Filed Oct. 14, 1948 INVENTOR.

2O 6 LU/LA/AM 0. MOKAN ATTORNEYS W. O. MORAN Oct. 27,1933

GAS HEATER 5 Sheets-Sheet 4 Filed Oct. 14. 1948 M5 mm X 0 m M MW A Oct. 27, 1953 w, o, MORAN 2,656,833

GAS HEATER Filed Oct. 14, 1948 5 Sheets-Sheet 5 (l/lLL/AM 0.MORAN INVHVTOR.

A T TORNE Y5 Patented Oct. 27, 1953 UNITED STATES PATENT OFFICE GAS HEATER William 0. Moran, Tulsa, Okla. Application October 14, 1948, Serial No. 54,451

11 Claims.

This invention relates to an improved heater which possesses features which enable it to be used for the safe and efficient heating of unattended buildings, vehicles and the like. This invention is a continuation-in-part of my copending application Serial No. 689,231, filed August 8, 1946, which is now abandoned.

While this invention is not limited to use in such structures, it is extremely well adapted for use in the heating of meter houses and other like buildings used in oil refineries, oil production fields, tank farms, and on pipe lines. For instance, it is customary on cross-country pipe lines or on refinery pipe lines which handle either natural gas, or liquid petroleum products, to employ meters, gauges and valves at selected points on the pipe lines. For convenience of observation as well as protection from the elements, it is customary to install a plurality of meters, or gauges, or valves at a given point and house the assembly of such meters, gauges and valves in a meter house. During warm weather conditions, such meters and gauges function in a generally satisfactory manner, but under freezing conditions, it has been found that the meters and gauges fail to record, or give faulty recordings, probably due both to the low temperature itself and to the condensation or freezing of any water carried by the gases or liquids being measured and controlled by the meters, gauges and valves. Attempts have been made in the past to provide satisfactory heaters for such meter houses, but so far as I am aware such attempts have not been successful.

It should be understood that there are certain very distinct problems which must be overcome in order to heat these conventional meter houses in a safe, reliable and satisfactory manner. In the first place, the meter houses are normally not occupied by attendants. They are visited periodically for the purpose of observing and recording meter or gauge readings and making valve adjustments. But such visits are sporadic and of relatively short duration. Consequently, any provision for heating a meter house must embody a type of heater which can function without constant or frequent attendance by an operator. In other words, it must be capable of functioning reliably in an unattended building.

In the second place, the meter houses are very frequently erected in isolated and exposed places where they may be subjected to winds which blow from every direction of the compass and over a large range of wind velocities. A heater for such anexposed meter house must be capable of functioning continually without being influenced by variations in wind directions and velocity, and particularly without being extinguished by sudden changes of direction and wind velocity. In the third place, at oil refineries or tank farms, or on pipe lines, there is always a distinct possibility of leakage of petroleum, particularly the more Volatile fractions of petroleum, and the contamination of the atmosphere with vapors of such volatilized petroleum vapors as well as natural ases themselves. At times, the concentration of such vaporized and gaseous products in the atmosphere forms a mixture which is capable of ignition, even explosion, if subjected to a flame 0r spark. Such conditions not only prevail outside of meter houses but can easily exist within the meter house, due to a pipe leak or faulty valve. A satisfactory heater, to operate under such con-- ditions must, therefore, be one which is itself not influenced by the presence of combustible gases and vapors in the outside atmosphere and at the same time must be incapable of igniting any similar combustible or explosive atmospheres within the meter house.

The improved heater, which is the subject of the present invention, not only satisfies the requirements discussed above but overcomes the disadvantages of all prior art devices of which I am aware. This invention, therefore, has for an object the provision of a heater which will func tion continuall and satisfactorily in unattended structures, such as a meter house. A further ob ject of this invention is the provision of a heater which will burn efficiently and uniformly without regard to prevailing wind direction and velocity and without regard to the presence of combustible gases or vapors in the outside atmosphere. A further object of the invention is a heater which will satisfactorily heat the interior of a structure such as a meter house without danger of causing fire or explosion even if the atmosphere within the meter house contains an appreciable content of combustible or explosive vapors or gases.

Another important object or the invention is the provision of a heater so arranged that the air necessary to support combustion within the heater is drawn from the outside atmosphere, the products of combustion of the heater are discharged into the outside atmosphere but the actual combustion of the fuel occurs within a heater casing at a point which is within the interior of the building or structure to be heated. Still another object of the invention is the provision of a heater which may be easily and cheapi ate size.

therefrom so as to leave an annular air passageway 14 around the exterior of burner tube 35. A

suitable plate 39 is welded to bafile plate 40 so as to provide a plate for attaching baflle 40 to the lower part of baffle 33. Two or more brace rods 40a are welded at their ends to the upper part of bafile 40 and adjacent end 3'! of burner tube 35 respectively. Plate 39 is also desirably welded to burner tube 35 adjacent end 31. It is preferable to weld elbow 44 to baiile plate 40 so that the parts comprising the assembly of burner tube 35, baffle 38,

baflle 40, elbow 44 and fuel nozzle 45 are in fixed, substantially non-adjustablerelationship. Bafile 40 is provided with an orifice adapted to receive a burner nozzle 45, which is connected by means of elbow 44 which in turn is connected with a fuel inlet pipe. 43, controlled by valve 42, to fuel supply line 4|. Burner nozzle 45 has a restricted fuel orifice 45a of appropri- The discharge end of burner nozzle 45 is inserted within the open end 31 of burner tube 35 and is substantially coaxial with the horizontal axis of the burner tube 35. The top of burner tube 35 is provided with a plurality of angularly disposed combustion slots 46, which as shown in Figures 3 and '7, depend to a point about midway of the periphery of burner tube 35. Adjacent the exterior end is of cylinder IS a suitable collar 8 is provided as a brace or support for flue Ill. Desirably, the interior of collar 8 will be threaded for threaded engagement with corresponding threads on the lower end of flue l 3 so as to provide a firm and practically gas-tight connection between collar 8 and flue It.

Turning now to Figure 4 of the drawings, the cylinder with its associated parts including hinged door 25, baffle I1, burner tube 35 and its associated baffles and fuel supply line is generally similar to the modification shown in Figure 3. As shown in the modification in Figure 3, the

' exterior end of the cylinder, with the hinged door 25, fuel inlet pipe 43 and the flue I0, is to the left of, that is exterior of, wall 5 of the structure to be heated. In the modification in Figure 4, the hinged door 25 and fuel inlet pipe 43 are both to the left of, that is exterior of, Wall 5. However, at the interior end of cylinder l5 adjacent end wall I6, is located collar [2 which except for its position is otherwise similar to collar 8 in the modification of Figure 3. Collar I 2 is interiorly threaded for engagement with a flue pipe l3 so as to provide an essentially gas-tight connection with pipe [3. If desired, to insure gas-tightness, a suitable caulking compound 5'! may be placed around the entire upper periphery of collar IE to seal the joint. Since collar l2 and its associated pipe l3 are located to the right of, or interior of, the wall 5, some modification of the interior of the cylinder [5 is desirable. An additional horizontal baflle 2c, affixed to end wall l6 by welding or otherwise, and also afiixed to the inner wall of cylinder [5, may be disposed above bafiie l1. Bafiie will extend almost across the entire length of the casing l but will leave a gap 2| to provide gas passage. As in the modification shown in Figure 3, the interior of cylinder 15 is separated into a lower or combustion zone 34 but in Figure 4 the upper portion of the interior is divided into two gas passageways 22 and 23.

As shown in Figures 6 and 7, the main fuel line 43 is supplemented by a pilot fuel line 68 the interior end of which terminates outside of but adjacent burner tube 35. It will be understood that the pilot tube 69 may be perforated and that its supply line 68 may be provided with any suit able valves for controlling the flow of fuel which may be ignited by opening hinged door 25 and by means of which the necessary ignition of the combustible mixture produced in burner tube maybe accomplished.

The detailed description of diagrammatic Figures 8 and 13will be covered in the portion of this specification which relates to operation.

Figure 9 shows a detail of a baffle plate, or collar, which is located within the combustion zone 34 and adjacent the fuelinlet end of burner tube 35. The notch or orifice 4| is sufliciently large to embrace burner tube 35 but to leave an annular air space 14, around the upper periphery of tube 35 i In Figure 12 the upper end of flue I0 is surmounted with a draft equalizing cap II. This cap has an imperforate top 41 so as to form a cular in cross-section and open at generally cylindrical cap which has an inner diameter slightly greater than that of the outer diameter of flue I0, and which may be provided with a suitable lock nut, or any similar device, for holding cap H in place at the upper end of flue III in fixed adjustment thereon. The vertical walls of cap H are pierced with a plurality of orifices or ports 48, preferably in uniformly spaced relationships, and preferably having a combined orifice area approximately equal to the crosssectional area of flue It. The arrangement of cap I I is such that the only exit path for flue gases is from flue I0 through one or more of the ports 48.

The air inlet end of heater. 1, that is the end closed by partition 18 and door 25, is preferably connected to a flame arrestor by means of a suitable adjustable collar, not shown. The flame arrestor, illustrated in Figures 14 to 17 consists of a cylindrical portion 50 of a diameter ap proximating that of heater 1 and adapted to be placed in alignment with the major horizontal axis of heater 1 and to the left of the exterior end as shown in Figures 1 and 2. A hood is mounted on the cylindrical chamber 50 by means of flanges 5i and may be additionally supported by means of braces 52. The hood preferably consists of a vertical closure 53, roughly semi-cirthe bottom. This vertical closure extends upwardly to a position somewhat above the central horizontal axis of tube 50 and is covered by an inclined roof 54 the upper end of which terminates in a horizontal flange or lip 55. The inner skirt 56 of the vertical wall 53 may not only be bolted or riveted to 5| but may also be connected with an interior bafiie 51 which is connected to skirt 56 by means of flange 58. As will be observed from Figure 16, bafiie 51 has a peripheral edge spaced apart from wall 53 so as to leave an air passageway between its outer margin and the inner surface of wall 53. Mounted within cylinder 50 are a plurality of screens 59, 60 and Bi. Where two adjacent screens are close together they may be separated by an insulating ring gasket, of asbestos or the like, 52. They may be additionally separated by an annular metallic ring or spacer 63. The several screens so insulated or so spaced may be held in position by means of a metallic gasket 34 at various points around the periphery of which may be afiixed suitable bolts and nuts 63. It will be observed particularly with relation to Figure 16 of the drawings, that the several screens 59, B0 and 6! are sufiiciently smaller than the interior bore of cylinder 50 so as to permit their being installed in spaced relation with re- Manner of opendtion "iineioi idtionbr the impravedireater ings. "Itwill b'e'liiidrstbbdthet the heater understdod that theiiee'teffia's Been "use Within striictiifes'finwhi'h' the tuibuleneein the combustion zone whi 'chfivill enn ngs ciently long to consume all oxygen in the air and starve the flames from burner tube 35. If this situation occurs, and all flames from burner tube 35 are extinguished, gas continues to flow through the burner, but of course, the burner itself ceases to function as a heating unit. Under such circumstances, unconsumed ga will be discharged from flue It and will not be permitted to be discharged within the structure to be heated, It has been my observation that where distance. Consequently, if any relatively dense gasoline vapors approach the lower edges of vertical walls 53 they may, insofar as permitted by bafile T, enter the lower part of the protective hood and flow toward the burner itself creating the possibility of a puff-back as described above. However, the provision of the upper air inlet passageway below flange 55 permits relatively pure air to enter through that passageway and flow thence toward the burner and combustion zone 34, greatly minimizing the chances of any flame, caused by a puff-back, from consuming all of the oxygen and extinguishing the flames from jet 46. It will be understood that baffle 5! may be disposed substantially horizontally or inclined downwardly, as shown in Figure 16, and in general will be formed of a metal of such gauge as will permit deflection andl adjustment thereof as desired. The disposition of the baffle 51 is such as will ordinarily prevent the passage upward of relatively dense gasoline vapors except if they are aspirated by air being drawn in around the edges of the baffle. Under such circumstances, the gasoline vapors will be diluted by the air and conditions will be created which will further minimize the opportunity for complete combustion of all available oxygen since such diluting air will increase the air added below flange 55. The arrangement is such that only in the rare event that a stratum of combustible vapors, such as gasoline vapors, is of sufficient depth to submerge the entire covering of the flame arr'estor will there exist an overall condition which will support a flame between screen 5! and air inlet door 25 which will consume all oxygen and cause the extinguishment of the flames from slots 6. Even under such conditions of extreme concentration of combustible vapors the propagation of the flame from the burner to the outside atmosphere is prevented by screens 58, (iii and 6i. i

After the air has passed through the flame arrestor, it enters thte various ports 26 in door 25 and is deflected downwardly by skirt 33 of bafile 35!. Some of the air follows a path upwardly over the top of baffle 4B and into the space between bafiles 4B and 38. A minor fraction of this air is aspirated and passes downwardly and into the open end 31 of combustion tube 3.3 where it meets fuel being discharged from jet 55a of tip 45. This air is the primary air which upon mixing with the fuel passes into the interior or burner, tube 35 thence through the burner slots 45 where it i burned. The ma jor portion of the air present in the space be- Iii.

38 passes through the slot 14 and thence in a direction initially generally parallel to the major axis of burner tube 35. The volume of air so passing in this direction is generally sufficient to supply the secondary air for complete combustion of the fuel. Air which does not pass upwardly into the space between bafiles 38 and 40 tends to flow below said baffles and into combustion zone 34 below burner tube 35. As the result of the combustion of the fuel and primary and secondary air, suflicient heat is developed in the space between burner tube 35 and baffle ll to expand the hot products of combustion in that space and to create a gas zone which is relatively less dense than the gas zone below burner tube 35. Consequently, any air not needed for primary air or secondary air for combustion and which is passing through combustion chamber 34 below burr-er tube 35 will generally be cooler and more dense, and will not tend to rise above burner tube 35. If, however, there is insuflioient air for complete combustion in the area above burner tube 35 and below hafiie I1,

tween baffles and some of the air from the space below may be drawn upwardly so as to supply additional sec ondary air. As they pass to the rear of combustion zone 34, in a direction toward end ll; of tube 1, the hot products of combustion and excess air become admixed, more equalized in temperature but without any undue turbulence. The mixture of such gases then flows upwardly through passageway I9, reverses its direction of flow and flows through zone 22 to the foot of flue Ill.

The draft equalizer cap H which is adjustably mounted at the upper end of flue In is, as stated above, provided with a plurality of orifices 48 which are spaced in a plurality of rows around the entire periphery of the vertical walls of cap II. The top of cap I I is sealed off with an imperforate plate 4'! so that any flue gases discharged from flue Ill must pass through orifices 48 in order to get into the outside atmosphere. Preferably the combined area of the orifices 48 is about the same as the cross-sectional area of flue l0. Consequently, where the outside wind velocity is zero, combustion gases which are rising through flue l0 may pass out of the ports 48 as readily and at substantially the same velocity as they are rising within flue Ill. However, where wind is blowing from a given direction at a velocity other than zero, the ports 48 on the windward side of cap II are subjected to somewhat higher the ports on the opposite side of cap II, that is, the leeward side. In fact, the ports on the leeward side are generally subjected to atmospheric pressure which is below that of the surrounding atmosphere. In other words, on the windward side there is a high pressure area, on the leeward side there is a low pressure area. When the windward or high pressure area is subjected to wind velocity which creates a pressure less than the stack pressure in flue I0, flue-gases may pass out through all ports in cap ll. When wind velocity'is such as to create a windward or high pressure which equals the stack pressure, ports 48 on the windward side of cap H are in effect sealed oil. However, the reduced pressure on the leeward side of cap I I is sufficiently below the stack pressure to permit flue gases to escape through the leeward ports rapidly enough to remove combustion gases at the normal rate of generation; When the wind velocity is great enough to create a windward side high presoutside air pressure than.

11 sure on cap: -l I which exceeds: the stack: pres-- sure; airis: permittedrto enter cap H. through. the windward ports. This tends .to create. a; greater pressure within the interior: of. cap. II but the tendency" is balanced by: the:- corresponds ing= reduction of pressure on. the leeward: ports: which: permits the flue gases: and: added: air to: be-discharged through said leeward.- ports; more: rapidly than when under the influenceiof; mere: stack pressure. Aconventional flue: such as; I which is not surmounted by a. draft: equalizer, would permit: wind: from any; direction to force" the draft' at the upper end; of fine. I0. and would tend to:' withdraw combustion gases more: rap.- idly than: they'woul'da normally be formed: withe intheiheater'. This, in turmwould increase the demand; for air necessary tosupport combustion andwould; seriouslymodify-the combustion. conditions withirt zone- 34:. By: installing the, draft equalizer cap: at the: top of flue-1 {0, increased external? pressure of. wind velocity;: regardlessof the :direction-. of the wind, does. not cause a. sudden or violently increased draftor seriously 'modify; the: combustion: conditions within, zone- Zone 34= is; therefore, maintained at all times underthewoptimum conditionsiof combustion for.- which it wasdesigned. Furthermore; by virtueoii' the: perforations in; the; door 2-5,- supplemented by. the-baffle- 30 and the? baffles 38- and-.40,, re-- gardless of. the;- d-irection. of the wind orof its velocity, the flow of: air through the ports 26 in door; 25- isf-maintained constant. No= sudden gusts of air are permitted to occur withinicomrbustion: zonce'3 i and; the. airwhich iss introduced throughdoor 7 is; separated-unto thepr-imaryr and. secondary ainstreamed;and. the. excess. stream, which flows quietly below burner tubes 35;. It; will: be observed; therefore; that atboth, the" airinlet; end; and; at the: fillfisfiBS exit, end. there. have been: provided; elementsswhich elims inate excessive; "drafts? and which 'throttleythe: air: inlet flow and the; combustion, outlet flow at. both ends: of; the-he.ater.-.

A. further important: featureroir. thee installation is the relatively} fixed and; non-adjustablez arrangement of; baffles: 40? and--38". with; relation: toburner tube 3-5 and particularly theopememi' 3:1? thereof; Battles: 40 and 38:. are: spaced apart-:- from each otherby; a: fixed distance- Which is; sufficient to: perm-it. a coniniolled'fiovw airibver; baffle" M1 and: unden'bafllew 38 so: as to supply the airrnecessary as; secondary, airfor? combustion. yet atthe same time; the; withdrawal, ofi 'az. small; part of i this; air: intorthej-i'nterior oii bumen tube 35.- fonthernecessauy primaryain The: fixed: relationshipi of; baflles; 4.0 and; 3% is; important. because: since the; combustion condi.- tions; im-combustion zone341- are stabilized bymeans.=.-of=. inlet door 2.5; and, draft equalizer H; I10? adjustment. of. air: or: fuel, flow is neeessarya. Thus, adjustment. by inexperienced personnel .in. the-fields; is-unneeessary and, anoided. In; fact, to eliminate field; adjustment: baffle 40. is. delib eratelywelded, to combustion tube 35 and to supports Mlmsoa as.- to:- insure againstattempts tormake' adjustments. in. the: field. Eurthermore,

the fuel. inlet tube 45. having been. initially se lected with: regard 110-9; 'fuel inlet. orifice 45a: to

. give a proper-fuel: supply, is deliberately threadsedz-into elbow M which isin turn weldedto hafileso. as; to. present: undesired adjustment. and. replacement of fuels nozzle-.- 45. From: the. foregoing, it. will; be seen that theflocation of: burner tube; 35 combustion; zone 34= is} selected with;

regard to; a. positionv which-.wills minimize. lence within. combustion. zona 34'; moreover, baffles 381' 811(11'4'112371182501 placed; and so prance tioned as to: provide for the: passage.- of: the.- I166."

-'. essary primary air: and: secondary. air to. supr portzcombustion of: a. selected fuel, as: intro.- dueedzinto the interior: of burner: tube 35 in controlled-Land required amounts, yet atthesame time the. air necessary for primaryair. andrse r P ondary air? for: combustion. is. bafiled: to; minimizeturbulence within; combustion. zone 34,. Particle lar attention. is called to. the: annular: space,- H; and to thepartial clearance formedlbetweem the: outer; (relatively smaller) marginal, outline; oi:

. baffle; 4|]. as: compared,- with; the-inner (relatively larger); marginaloutliner-of battle: 38..

The; arrangement of; theburnen slots in: the: tube 35 isa. feature: ofconsiderable importance. A. combustion tubezhavinga, length. of about: 18. inchesand: an; external diameter of about-1. g, inches, and an, internal diameter of about 1. inch, and inywh-ich ten burner slots are spacedabout. an. inch. apart has: been found: to. give excellent; results; Such slots; which have a. width of. about;

. 1 5th; of'an inchand which extend from the;tog-.

of? burner tube; 3.5.: to: a... point about oppositethe; major horizontal axis of the tube. may desirably" be: disposed at an. angle of; about= froma-the vertical; Under: such circumstances. therelation ship-between the. leading edge 1-0 and the-trailing. edge H: of each burner slot;.asillustratedinFi ure. 1-8: ofthe drawings, existsso that'- secondary, air flowing alongthe surfacerof burner tube 3.5- is, not, deflected downwardly and into the burner slot: so; as. to snufi; out. the'flame The burner: slots, however, donot have, tobe. installed at. an angle. of about 455 from the horizontal, in fact, I- have? found that if the slots are arranged atany angle. from, the horizontal between: aboutl5 and: about: 855, a flame is produced. which will burn. con stantly. and; without dangerof being snuffed out. by. secondary air currents. I. have. tried, slots; whichare placed; atan angle of. 90,. from-the. hm.- izontal and in lieuof. slots, I have also tried orifices disposedat. a variety of angles. With vertical slots and with the orifices there is..a. constant. danger of the flame-being snuffed outby second ar-y'air: In fact, if the; slots are installedwithin. the-uppermost limits of the 15? to 855 range, men,- tioned: -above,, I find it desirable. tamodify. the;

' slots, either: as... shown in Eigure.19l or 20. to.saf,e.-

guard" against; any downward deflection, of the, secondary, air and, snuffing outcthe flame. As. shownimEigure 19, one arrangement for. avoiding downward: deflection; is the placing of a bead o1.

smalr baille immediately in front of the leading edge. 10; of. each slotpor alternatively, as shown, in; Figure 20, by machining-off of. the upper; por tionofjtrailing;edge-H: of the slot. Obviously, a. combination, ofthese two. modifications could be employed, that is, by using both a bead I2. in. front of theleading edge of theslotand machining-offa portion13 of the trailing edge of the slot. In. fact, by'utilizing a bead or barrier 12 on the lead ngedge of the slot, or by utilizing the ma.- chined-ofi margin of the trailing edge 13 of theslot, or; preferably by utilizing bothof said. feartures, theslots maybe disposed in the tube 35.at angles, greater than and even up to. from. the horizontal, It will be understood that while I have referred toadding a bead or machiningofi, other methods of accomplishing these results. may beemployed, as for example casting the tube with slots of desired angularity and edge forma-= tiQIL The location and disposition of the baflie I! is of importance. Being located just above the flames from the several combustion slots, bafile I1 is heated not only by radiant heat, convective heat, and heat conducted by hot products of combustion but, in fact, is heated by direct impingement of the flame. Bafiie l1, therefore serves to heat further the combustion gases which have left combustion zone 34 and have entered zone 22 so that these gases in turn can give up their heatto the walls [5 of heater 1. Additionally, since baflie I! is in direct contact at its fixed end, and on both sides, with the walls 15 of heater 1, the baffle conducts heat to walls I 5 so that heater 1 becomes more effective in transmitting heat to the space being heated.

I prefer the modification illustrated in Figures 1 and 3 of the drawings because that modification accomplishes the primary objectives which are, the utilization of a heater which may be readily inserted into a given Wall of an existing structure without requiring more than a single opening in the wall. The same, of course, applies to an installation of this modification of the heater at the time of erection of a given structure. Additionally, this modification of the heater has the advantage of an arrangement which permits direct access to the heater from the outside of the structure for ignition of the pilot light and for any cleaning or repairs which may be necessary after prolonged used. Fundamentally, however, this modification of the heater possesses the virtue of having an air ingress door and a combustion gas fiue which are both entirely outside of the structure being heated and both at the same end or side of the structure, yet the actual combustion within the heater takes place in a space which is physically within the structure being heated, but the heater is entirely air-tight so that no open flame may create the danger of explosions or combustion within the structure. Consequently, practically all of the desired heat given off by the heater is imparted to the interior of the structure in a'safe, simple and reliablemanner. However, it may occasionally be desirable to heat a particular set of valves, or meters, or some other object within the structure, at interior points which are somewhat remote from the actual heater. Under such circumstances, it is not necessary to limit the arrangement of my device to the modification shown in Figures 1 and 3 of thedrawings. The alternative arrangement shown in Figures 2 and 4 may be utilized where it is desired to install the air ingress door and the heater itself throughone wall. while permitting the flue gases to pass 1 through an opposite wall or even an adjacent wall while heating remote valves or meters. ,To permit such a modification of use, the cylinder i5 of the heater may be modified to the extent necessary to change the position of collar 8 to the opposite end of the cylinder as shown at 52 in Figure 4. A

suitable connection l3 may be inserted into collar l2, preferably by threaded engagement, and

to insure against any combustion gas leakage it may be desirable to seal the joint betweencollar I 2 and extension 13 by welding or by caulking with a suitable compound as at 61. In such a modification extension !3 may be directed to the oppositewall of the structure or may be provided,

with a right angle bend so as to take it out of an adjacent wall of the structure at any selected point. Extension l3 may be integral with flue It! or may be formed by jointed connections. It may also be desired, in order to provide for the proper discharge of flue gases from the burner as shown in Figure 4, to install an additional bame 20 above and generally parallel to the primary baffle IT. This, of course, will create an additional combustion gas exit zone 23. In order to prevent undesired obstruction to the free flow of the combustion gases through zones 22 and 23, it may be desirable to make casing l 5 of a somewhat larger cross-sectional size than would be required for the modification shown in Figure 3. For example,

13 where cylinder l5 of Figure 3 may desirably have an 8 inch diameter, cylinder l5 of Figure 14 may desirably have a 10 inch diameter.

Furthermore, under some circumstances it may be desirable to modify the embodiment shown in Figure 3 so as to permit installation through one wall of a given structure and discharge of the combustion gases through an opposite wall by merely extending cylinder [5 entirely through the structure so that the air ingress end would be position as shown in Figure 3 yet the flue gas discharge end would be as shown in Figure 4. This modification as well as the modification in Figure 4 both have the virtue of withdrawing air for combustion from the outsideof the structure and discharging the combustion gases outside of the structure.

In the foregoing specification, reference has been made to fuel for the burner without expressly describing the fuel. Conventional fuel gas has been found to be a satisfactory fuel, particularly in the vicinity of refineries where there is a large source of either manufactured gas or natural gas. However, I do not wish to be limited In general, any when vaporized may be used in to those specific types of fuel. fuel which may be vaporized, and will form a combustible mixture,

my heater. Thus, not only natural gas, refinery gas,but also the so-called propane, butane and mixlight, normally gaseous hyavailable as fuels, may be gas, or manufactured bottled gases, such as tures of the relatively drocarbons which are used. With natural gas, or manufactured gas, the conventional gas pressure of 2 to 6 ounces per square inch gauge may be employed. By the selection of a fuel jet 45 with an orifice 45a of a selected size, the so-called bottled gases which are commercially obtainable in cylinders compressed to much higher pressures may be used by installing a suitable line 43 and by using a somewhat smaller orifice 4511 than is ordinarily used for low pressure gas. With such alternate fuels, no other change in the arrangements of bafiies, burner tube. or burner tube slots is necessary, so the burner is adaptable to a wide variety of available fuels. I

In this specification I have illustratedthe use of my burner in heating meter houses and the by way of illustration only. H

like. Such use was It is contemplated that the burner may be used to heat other structures such as warehouses, work. like.

sheds, garages, military barracks and the Moreover, the heater is not limited to use in heating, fixed structures, but may readily be used in heating vehicles, such as troop transport trucks and the like. In heating vehicles the so-called bottled gas fuels would be readily u able,

same advantages which flow from the use of my burner in connection with isolated and unattended structures subjected to high wind velocities in exposed places would also be apparent in moving vehicles since one of the important virtues of my heater is its ability, to function safely and,

reliably without regard to wind direction and velocity, under conditions which are frequently found in vehicles moving even at high speeds.

pressure reduction valve in talb'afile ,as it passes over 1:- Inrazgasl-heater for;heatinaanenclosurehaveinseat leastaone everticalzwall; saidaheater beinez llowed-mo ,-withdraw air forlcombnstionlfrom :the out-sidesatmosphere-rand;to:- discharge 1 flue gases into-;therontside .atnmsphere whilerheating-lthe in: tenors o.-, -the renclosure a laterally closed, casing; adaptedimbe partially inserted-throughthe wall... ofssaichv enclosure, ,anperforated, air. inlet: door, at theeendaofqsaid Icasingqadapted to be positionedw exterion of-g saidwal-L; atfiue; gas dischargecondmt connected with said-casing' to:dischargegfluebgasesr exterior ofnsaidt-enclosure, a; burner, tube within saidcasing at aapoint-lin, spaced relation, to. ands, interioraofQsaid -ain inletv dean, means .rtol stabilize-:1 5 the rrate of air flowr-intolsaidhcasing, the. rateoi flue gasndiseharge fromsaid, casing and ,thejloyq oiypriinaryi;andzsecondary. air to said burner. tube, said'stabilizin fmeanscomprising parallelgverticalp, bafllesl extending generally transverse, to; said burners tube/and disposed; in, spaced, predeter, mined;- relationship -between said; air inlet door and saidyburner, tube. v

2.; Aagas theater. oithe characten described 111,. claimnleincluding anhelongated. .horizontaL baffle 5 positioned in spaced relation above said burner, tuber andcsaid demand-attached towthe mter or of'saidl asingalonge ach side and at itsend atv theldocrvendcofrsaid casing but in spaced relation from-said-casingatits end opposite saidldoonend, whereby said secondary air, passes betweenthe upper-portion ohsaid burner; tube and.underneathv ot said; horizontal, baffle,-.,said flue. gas discharge, conduitvbeing connected =,t0 ,the .upper. portion ,of; saidnasing above-saidrbaifleandl atihe doormen ofzsaidl asingl.and!meansiorvsupnlyi as ous. met, to lthe; interior, at. said burner: tube, a said; burner. tube being, open atfiitslend .adiacentsaid aim-inlet .door v and ibeing closed atits ORDQsiteend a; and-having a niuralitybi parallel .combu tionslots 4 disposed inthe upperlhalfv thereof ,-.,sa,id slutssbcln 'r. disposedlatl an angle, of between; about 15 and; aboutniidi from. the horizontalr axis. of the. tube andeextendingvupwardand toward. the casing end 7 opposite said doora end zwhereby ga es orcombustiontfromt saidpburner ztllbQSlQtS, passundellncath saidhorizontallbaflie toward, the end of the casmg ODDOSitGVthG vdooroer,1d,t1c1ere )f,,.ar.1.d thence upward insaidcasmaatthe endofsaid bafileandthm gh the casing;to.saidiiue.gasldischarge onduit con: 0 nectedtdsaid casing Elli A, gas, heater of the v character described, n claimJ, including an,lelongated'horizontal' baflle positioned in spacedrelation above said burner tube and said door and attached to theinterior of lsaid casing along each side and; at its ,end at thQliiQOI end of saidcasingjut in-spaced relation frommsaidlcasing at its end; opposite saiddooh end whereby said secondary, air passes between the upper portion of said burner tubeand underneath of. said horizontal baffle, said flue gas dis-, charge conduitbeinglconnected tothe upperportiomdfjsaid casing above, said bafile and at. the do9r,.end...o.f said casing. and means, for supplying aseous tfiielltovthe. interior, of ,s i bur r. t b 05 saidlburnerntube being open at, its, end adjacent saidv airuinlet-doorh and being closeoL at its one positeendand having aplura ity of par ll l corn: bustion slotsdisposed transversely in the up er halfjgofusaid tubasaidslots each havingits edge adj acentsaid open end of said,tube elevatedabove. its opposite edge sgas tovprevent downwarddefle ti n. oilsaidsecon r irrpas e v r the-t p, ofisaid burner tube and underneath said horizon- I the tubefrom its op' en 75,

16: end'gtoward itsg closed-l, 6nd, Sflid, S1QbSB-&1S0 bfiin disposed at an angle 30L} between about: 15x?v and about: 903 fromsthes horizontal; axis: of the tubee as measured upwardfrom;,the horiz on tal\axisdot thelburner at-its end at the.closed@end, of the;

burner-tuber,

4. Arg-as'. heater/of zthe; character: describedrina claim 1: including a; first-elongated horizontal: baffle; positioned in spaced relation; above esaid; burner tube, and said door and "attached .to (they interior-.of said casing; but in spacederelationr from said casing-i at: its end :opposite; said: :door; endi vwhereby saidrsecondaryair passes between the+upperlportion of rsaid-burnerztube and-,unQenrneath of said; first, horizontal abaflle and at second :1 horizontal bafile positioned,inflspacedr relation: abovetsaid first, horizontal ibaffleeand attached to the interior .ofnsaidl-casingialong each, side andat 1 its end;.oppos it.e;to,-.-said door ;b.ut,,in spacedmelas tionrfromsaidcasing at the. door, endithereot said fluegasdischargeconduit being conneotedrtothe:i upper, portion-of saidcasingeaboye-saidf second,

bailie -end at; theopposite to the doon endi-ofnthecasing 5,- A fluid fuel heater; adapted for... heatin a walled enclosure said :heatencomprising a: casing having an aireinlet. endpartially. open :for. com: munication I with the atmosphere: andrhaving its opposite :end closed-,- said casing ,bein adapted for; partial insertion through-a, lwalliof. saidlenclosurel with: the air inlet: end kthereoi; being v exterioraofn the enclosure, afiuidufuehburnerwtube within/Said; casing, a fluid v,fuel duct adaptedltovlead fluid fue1.-; to said, burnen tube fon combustion .thereby,, parallel vertically disposed;bafllesld snos e-adajacentl said. burner. tube transyerse I theretoaahdl intermediatetsaid open: air? inlet ,endof ,the .cas:, ing and. said burnentube,andadapted tostabil zc an: introducted through saidairI inlet. icasinghend and produceastabilizedjlowrof c mbustion ease geneiiatedvbys e combustion.-ofbsaidnuidlfuelia, combustion gasoutlet insaid casingPand-atleastl oneueddition l tbaflleuwithin. said. casina disnosed between .said;ib .ner and said "outlet adapted .t0..- directnthem flow, of .combusti0n-eas.es. iromlsaid, burner. u e h o said .c si eand ,t l aidtoutlet 7 v 6,. .The hea er efinedin claim 5.; when invsaidl combustionsa O tl t is. disnoseda iacent aid" an; inlet. end of said casing ,andinthe portionpf saidg'casingwhich is adapted to bedisposed1ex-Vv terior of said enclosure. 7

7.. The heater in claimfi wherein said casilng isl a horizontal1y,disp osed elongated cylinderf nd;

wherein said burner tube is slotted and 'jis dis: posed substantially parallel to the horizontal axis,

of said-cylinder. v

8, Theheater, defined in claim}? wherein the slots in said burner tube are positionedadjacent the top surfaceof-sald burner tube, are parallel to-each other; and are disposed at" annanglewof" between about 15 and about '85? as measured from a horizontal plane parallelto the-said axis of said cylinder.

9. The heater definedin claim 8 .Whereinthat edge;- of each burner ,slot, which is nearestthel airinlet end oi sai'd casing is elevated above the 'corresponding portion of that edge of said burner;

slot; which is more remote from said air inlet end, of said casing. I i

10v In a fluid fuellheater comprisin lmeansl forming a combustion chamber .oneendof, which has anair inlet opening and the ,othernendnoi, which hasa combustion gas 7 discharge Opening adja en h a? fluidafuel burnen ubflis.

17 posed entirely within and in spaced relation to said combustion chamber, said burner tube being closed at the end thereof adjacent the discharge opening of said combustion chamber, the other end of said burner tube, which is relatively adjacent but spaced inwardly from said air inlet end of said combustion chamber, being provided with an opening adapted to permit the introduction of primary air and fluid fuel for admixture within said burner tube, means for supplying fluid fuel to within said burner tube, said burner tube having on the upper portion thereof a plurality of parallel combustion slots, said slots being disposed at an angle of between about 15 and about 85 from the major axis of said tube and being inclined upwardly in the direction of the closed end thereof, and spaced substantially vertical baflles disposed adjacent the air inlet end of said combustion chamber and the air inlet end of said burner tube for controlling the flow of primary air to the interior of said burner tube while permitting and controlling the passage of secondary air adjacent and exterior of said burner slots.

11. The heater defined in claim 10 wherein 18 those edges of said slots, which are relatively adjacent the primary air inlet end of said burner tube, are elevated above the opposing edges, of said slots, which are relatively adjacent the closed end of said tube.

WILLI-AM O. MORAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 939,925 Schellhammer Nov. 9, 1909 975,868 Ishii Nov. 15, 1910 1,162,205 Ashorn Nov. 30, 1915 1,811,323 Lejay June 23, 1931 1,839,655 Dobbins Jan. 5, 1932 1,842,625 ORiley June 26, 1932 2,158,643 Wacek May 16, 1939. 2,192,920 Linoh Mar. 12, 1940 2,400,117 Holthouse May 14, 1946 2,420,599 Jurs May 13, 1947 FOREIGN PATENTS Number Country Date 27,807 Great Britain of 1913 354,153 Great Britain Aug. 6, 1931 

